一起肠聚集性大肠埃希氏菌引起的食源性疾病暴发调查分析

Investigation and analysis of an outbreak of foodborne disease caused by enteroaggregative Escherichia coli

目的调查处理一起引起学生集体腹泻事件,分析本次事件的原因和可疑危险因素。方法通过查阅学校医务室就诊记录、考勤记录、就餐消费系统刷卡记录和医院就诊记录等主动搜索病例,开展病例个案和现场卫生学调查,采集相关样品进行实验室检测等,运用回顾性队列研究判断本次食源性疾病暴发事件的可疑餐次和食物。结果通过访谈、个案调查、实验室检查等共搜索到病例217人,临床特征主要为腹泻(腹泻次数≥3次/24 h占比62%,135/217)、腹痛(47%,102/217)等;从生物、食物原料和环境样品中共检出肠聚集性大肠埃希氏菌(enteroaggregative Escherichia coli,EAEC)毒力基因阳性样品55份,分离到EAEC菌株28株,其中27株进行脉冲场凝胶电泳分型,共形成A^Q 17个型别,呈高度多态性。可疑食品是5月30日晚餐的凉拌椒麻鸡。结论该起事件是由学校食堂配餐引起的一起肠道聚集性大肠埃希氏菌所致食源性疾病暴发,建议监管部门加强对学校食堂的监督管理,提高食堂从业人员食品安全意识,预防类似事件的发生。

Objective To investigate and deal with a mass diarrhea incident of students,analyze the causes and suspicious risk factors of this incident.Methods Cases were actively searched by referring to medical records of the school,attendance records,swiping records of the meal consumption system and medical records of the hospital,case studies and on-site hygiene investigations were carried out,relevant samples were collected for laboratory testing,etc.The suspicious meals and foods in this foodborne disease outbreak were judged by a retrospective cohort study.Result A total of 217 cases were found through interviews,case investigations and laboratory tests,and the main clinical features were diarrhea(diarrhea≥3 times/24 h accounted for 62%,135/217)and abdominal pain(47%,102/217).The 55 positive samples of enteroaggregative Escherichia coli(EAEC)virulence gene were detected from biological,food raw materials and environmental samples,and 28 strains of EAEC strains were isolated,of which 27 strains were classified by pulsed field gel electrophoresis,17 types of A-Q were formed,which were highly polymorphic.The suspicious food was the chilli pepper chicken for dinner on May 30.Conclusion The incident was caused by a food borne disease outbreak caused by EAEC in the school canteen.It is suggested that the supervision department should strengthen the supervision and management of school canteens,improve the food safety awareness of canteen employees,and prevent the occurrence of similar incidents.